Tool for cutting or turning



July 4, 1939- A. J. BERG Er AL 2,164,303

TOOL FOR CUTTING QR TURNING Filed Dec. 8, 1937 l '2 sheets-sheet 1 Fig.6 Fig. Y

F1' .l0 'Fig/1] INVENToRs ALFRD J BERG 0 JOHN HUSE ATTORNEY July 4,1939. A J BERG -r M 2,164,303

TOOL FOR CUTTING 0R TURNING NVENTORS ALFRED J. BERG BY JOHN O. HUSE waATTORNEY Patented July 4, 1939 UNITED STATES Toor. Foa CUTTING onTURNING Alfred J. Berg, Portsmouth, N. H., and John 0. Buse, UnitedStates Navy -Application December 8, 1937, Serial No. 178,700

Giaims. (Ci. :t9- 95) (Granted under the act of March 3, 1883, asamended April 30, 1928; 370 O. G. 757) In the prior art, metal has beenturned by a lathe. a screw machine or other turning or cutting toolmerely to transform the metal into-useful articles of the desired shapeand dimensions, and the treatment of the cut or turned metal articleslto increase their strength or toughness has been accomplished only as aseparate operation by a wholly different class of equipment and skilledWorkmen. Our present invention accomplishes these two independentpractices by different facilities and operatives by and simultaneouslywith the cutting or turning of the metal to the desired dimension whichwe have found rapidly, efficiently, and Without other handling orprocessing to increase the strength, toughness and surface density ofthe cut or turned metal articles to dierent degrees which We have foundvery satisfactory and advantageous in many different uses and classes ofservice of such articles.

In the prior practice the cutting or turning problem has heretofore beenapproached and solvedisolely from the aspect of most readilyandeconomically reducing the metal to the dimensions present invention isthat the prior practice has been to cut or turn off the required metalwith the least expense of time and power and the least duty and wearupon the cutting or turning tool.

In the practice of our method we increase thev cutting stress upon thesurface of the metal being cut or turned and thereby transform thecharacteristics of the metal at andv adjacent the sur- Vface being cutor turned to afford the requisite strength, toughness and surfacedensity which will afford satisfaction in the use and class of servicewhich may be required of the partor parts thus cut or' turned. Thisincreased strength, toughness and surface density of the cut or `turnedmetal may be accomplished uniformly throughout the whole, or localizedin portions,o f the metal required to be cut or turned in 'accordancewith our invention. Such cutting or turningmay, according to ourinvention, be of uniform,` different or varying diameters as well as'end cuts, turnings or ,other cutting; and substantial lengths'of radialas well as longitudinal turning or other cuts may be simultaneouslymade, according to our invention, thereby transforming thecharacteristics of the cut metal.

More specifically, our invention attains the stated transformations ofthe characteristics of the cut or turned metal by the cutting or turningtool being designed and adapted to cold work the metal being cut as wellas the metal beingre- 5 moved by the cutting operation in accordancewith our method. Such cold' working may diifer in kind and degree indifferent portions of the article or differently in the extent of thecut, turned 0r otherwise machined surface of the article, as may bedesired, according to the design of the cutter or our method of usingthe same, or both. l

Much research has been given in the past to cutting tools of differentkinds as to the different angles formed by the faces ofthe cutting toolitself, such angles being known as cutting, clearance, top rake, andside rake. Such investigation has resulted in the development, utilizedfor many years, of such angles as will cut different kinds 4oi! metalwith the least powerand wear upon the tool. Such power and Wear meansless thrust of the cutter upon the material being cut, as well as lessliability of affecting the characteristics of the material being cut.

In the attainment and practice of our invention g5 little change need bemade in the cutting tool heretofore found most efficient for the cuttingof each different character of metal, except in respects opposite to ornot in accord with prior teachings in the art. These changes are in thetop rake and the side rake of the cutting portion of the tool andfunction to cold work the metal as the same is cut to the desired sizeand shape and by the tool which performs such cutting. This cold workingtransforms the metal forming the surface of the cut article andincreases the strength, toughness and surface density of such metal veryexpeditiously and inexpensively while the same is at atmospherictemperature except for such heat as may be generated for such cutting.This transformation, occurring simultaneously with and occasioned bysuch cutting, we have found veryv satisfactory and advantageous in manydiii'erentuses and classes of service of articles formed by suchcutting.

Other objects, advantages and accomplishments of our invention will berendered apparent, in the course of this specification, to those skilledin this art.

In the drawings, Figure 1 is an enlarged 50 diagrammatic viewillustrative of our invention. in which the parts are shown incross-section with irrelevant portions thereof broken away;

Figs. 2 and 3 are cross-sectional views of modiiications of the toolshown in Fig. 1; 56

siev'sucn view amm: :o m. 4. different curvature for thecutrrnteievauonvleworthemtr of Fig. 1 having different numbers of nicksgrooves therein; Fig. 16 a cross-sectional view typically of aportionofanyarticleanyof the surfacesof which may be cut or turned by acutting or turntool. j The article il represents any article having anyor all of which may be cut or turned in accordance with our invention.

Our invention may be most readily and broad-4 desired dimensions by acutter Il having a cutting edge I2 having clearance surface il, siderake surface Il and bottom surface I4, shown typically in Figs. 4, 8 andl5. The surface Il of article Il has, in the instance shown,beenpreviously cut by cutter Ii, and surface il of article Il is shownpartially cut by the succeeding action of cutter il. 'Ihe top and siderakes of cutter Il, represented by its edge I2 and surface il, so actupon the metal of article Il being cut by cutter Il as to exert pressureupon such metal beyond its elastic limit. Such pressure transforms themetal on opposite sides and somewhat in advance of the line of cleavage,represented by the successive surfaces il, i6, as to increase thedensity of such metal, which may be indicated by the stippling adjacentsm'faces Il, II, and on the shaving I1 being cut from article Il. Whenthe article i. is of copper, for

' instance, the surfaces il, Il are bright, as is Ila of shaving theside rake surface I8 of tool Il.

the surface IIa of shaving I1, while at and below the point Il the metalcomprising surface I1 is further transformed from a bright to a dull orfrosted surface appearance which continues throughout the extent ofsurface Ila of shaving I1. Buch transformation takes place as the metalof article Il, comprising shaving or chip Il, is deflected at a wideangle from surface Il laterally downward with its surface Ila in firmfrictional contact with Such deflection further subjects metal ofsurface ltd, and of surface Il adjacent point' Il, to compression stresswhich results in a permanent increased density of such metal, whosedensity had been increased beyond that normal for the metal of articleil by the preceding cut which resulted in surface Ii. Thistransformation of the char- ,rsasos v by as laresideelevationviewsofthe.

acteristicsofthemetalofshaving i1 tendsto increase the magnitude of thecleavage thrust of cutter Il uponthemetal ofarticle I0 by toughening themetal of shaving i1, 'and thus increasing its reluctance to deectionover the side rake surface VI8 of tool Ii.-

When surface li of articlek il has been uncut cutter li the metal ofsuch surface, as well of the outer surface of chip or shaving I1initially cut therefrom, is of the untransformed characteristics of thevirgin metal of article i0, except the heretofore describedtransformation occurring at point Il.

The top and side rakes of cutter ii may be normal for the kind of metalor alloy to be cut with such cutter, in which case one or both of suchrakes are provided with means which cold works the metal tosubstantially the above stated characteristics as the same is being cut.One form of such means is disclosed in Fig. 2 in which the clearancesurface im and the side rake surface ila of tool Ila, having cuttingedge I2a, are to be understood as normal for the kind of metal or alloyto be cut or turned by such tool. However, the top rake of this tool isincreased to afford the required magnitude of its thrust upon the metalof article i0 to be cut or turned by tool ila to afford the desiredincreased density of the metal. This top rake is so increased, in thisinstance, by the beveled surface |211 extending from cutting edge i2a tomerge with, and at a more abrupt angle than, the side rake surface ila.An additional form of such means may be provided on the tool lib of Fig.3, which is the same as tool Ila of Fig. 2 with the addition of one ormore narrow and shallow nicks 2i in cutting edge I2a. A groove 22,corresponding and registering with each nick 2l, extends downwardly fromeach nick' 2i across at least a portion of side rake surface Ita,preferably at a less abrupt angle than said surface Ila and at an anglewhich may be more abrupt than or equal to that of said surface ilaaccordingly as said groove 22 extends partially or wholly across saidsurface ila. The tool of Fig. 3 will cold work the surface metal ofarticle lll, cut or turned thereby, to an extent, substantially in excsof that possible with the tool of either Fig. i or 2, dependent upon thenumber of nicks 2| `and grooves 22 therein. The nicks 2l and grooves 22,or other such means, may be arranged in number and at places in thelength of the cutting edge I2a where the metal of the surface of articleil is subjected to greater wear or is for other reasons required to bestronger or less ductile.

The cutting tool shown in Figs. 10 to 15 inclusive, disclosessubstantially the same tool indicated in Fig. 1 having the wide angledside rake surface Il, but provided with a different number of nicks 2|and grooves 22. The cutter or turning tool disclosed in Figs. 4 to 9inclusive, has its cutting edge i2 arched and its side rake surface Ilarched longitudinally and transversely. The function of the straightcutting edge I2, Figs. 10 through 15, having one or more nicks thereinand of the arched cutting edge i2 of Figs. 4 through 9, is to increasethe length of the cutting edge. This increased length within a givenspace increases its cutting thrust upon the metal being cut or turnedthereby, which correspondingly increases the cold working effect uponthe surface of article il being cut or turned. 'I'he angle of the siderake surface i8 of the cutter i I andthe grooves 22 therein associatedwith the nick or nicks 2I, in cutting edge- I2 also increases the coldworking effect upon the surface of are ticle III being c ut or turnedthereby. Each voi! the nicks 2I in cutting edge I2 further cold ,Workthe metal of the surface of article I being cut or turned thereby, inthat there is a flowage of metal along the sides of each nick 2| towardthe low point thereof while the cutting edge I2 is engaged insuchcutting or turning. The arched cutting edge I2 of Figs. 4 through 9,also further cold Works the metalof the surface of article III being cutor turned thereby, due to the same causing some flowage fromthe hightoward the low point or points in such arched edge while the same isperforming its cutting function. Such arched edge I2 further cold worksvthe metal of luctance to the passage of the severed metal over at leastthat portion of the side rake surface I8 of the tool II which is withinthe pocket area bounded on one side by the arched edge I2, and on theother side by a line passed between the separated points upon saidarched edge I2 representing the width of the cut of metal being made bysaid arched edge I2.

The provision of nicks 2| in the arched cutting edge I2 of Figs. 8 and 9increases the cold working effect of such cutting edge, while theprovision of the grooves 22 upon the-beveled and arched side rakesurface I8 of the cutter or turning tool II of Figs. 8 and 9, alsoincreases the cold working effect of the arched and bmreled side rakesurface I8 of the cutter or turningr tool shown in Figs. 4 through 7.

The grooves 22 shown in Figs. 8 through 11 are curved, while those shownin Figs. 13 through 15 4 arel straight and at a slight angle. These varythe reluctance of passage of the `surplus severed metal over the siderake surface I8 of the tool I I, according to whether such cutter orturning tool is cutting in a straight line or in the arc of a circle.

In the development of our invention we have developed a method, andprovided means for its economical and efficient practice, ofsimultaneously'making two cuts at substantial angles to each other insuch a manneras also to thereby cold work advantageously the metal ofboth of these surfaces of article III being formed thereby. One of thesecuts has heretofore been explained.

The method of making and the means for practising the second cut at asubstantially different angle simultaneously with the making of thefirst stated cut, will now be explained.

When making only the first cut the characteristics of the tip orouterend of the cutter or turning tool I I are inconsequentiahfbut whenthe same-cutter or tool II'is equipped to simultaneously make both ofthe cuts while cold working the metal of thesurface of article III beingformed thereby, the characteristics of the cutter or tool II areconsequential.

In the instance shown in Figs. 4, 5, 8 and 9, the tip or outer end ofthe cutter or toolI I is provided with a cutting edge |27 joining withand extending laterally downward from the outerend of the cutting edgeI2. The angular length of the cutting edge |27' exceeds the thickness ofthe surplus metal of article I0 desired to be removed at a singlecutj'While the cutting edge I2 is functioning to cut the metalv at oneangle, the edge |29' simultaneously functions to cut the metal at asubstantially different angle -that may be'desired. 'I'he cutter ofFigs. 4, 5, 8 and 9, as well as the cutter of Fig. 11 to be hereinafterexplained, produces an angle at the juncture of the -cutting edge I2. Atthe juncture of the edges I2 and I 2n the adjacent surfaces of thecutter II is provided with a nick I2m, Figs. 6, 'l and 10, whose walladjacent said edges I2 and I2n ex- `\tends downward more bluntly thantheangle at which the side rake surface I 8 extends from said edges. Inaddition to making said curved juncture between the differently angledsurfaces of article I0, -said nick I2m further cold works the metal ofarticle II) at said juncture by increasing the length of the line ofcleavage normally afforded by the nick as well as by the increase,within the area of said nick I2m, of the top rake of the tool of Figs.6, 'I and 10, which more extensively cold works the metal of article IIIbeing cut by the cutting edges I2, AI 2m, at the margin of nick I2m.

The cutter or tool of Fig. 11 is provided at its tip or outer end with acutting edge I2p which is, in theinstance shown, at right angles to thecutting edge I2, said edgesbeing joined by corresponding angles. 'I'helength of cutting edge |211 is adapted to exceed the thickness of thesurplus metal to be cut or turned from article III at any onetime. Thenick I2m is formed at and adjacent the intersection of said edges I2 andI2p. The cutter of Figs. 12 and 13 is provided with the cutting edge|27' as heretofore explained in connection with Figs. 4, 5, 8 and 9.

The cutter of Figs. 14 and 15 is provided, in the instance` shown, witha half portion of a nick 2Ia in the tip end of the cutting edge I2, fromthe bottom of' which nick 2Ia extends laterally downward from the edgeI2 a cutting edge |27'. This cutting edge I2c may extend at the sameangle at which the side rake surface I8 of the tool II extends. In suchside rake surface I8 adjacent the cutting edge I 2c is formed half of agroove 22a. The metal cut by the half nick 2Ia is further cut by thecutting edge I2c which extends at a substantial angle to the cuttingedge I2 and which cutting edges I2 and I2C join at the bottom of thehalf nick 2Ia. The half nick 2Ia, its half groove 22a, and the cuttingedges I2 and I2c associated therewith, further cold Work j the cuttingedge of tool II of Fig. 8, being inclined equally in opposite directionsfrom the center of the length of such edge, occasions, while the same iscutting, a flowage of metal in opposite directions along such edge, andproduces a more uniform cold working of the metal of the surface ofarticle I0 being cut thereby. Y

'I'he article IU may be of any kind of metal of desired shape', a partor all of whose surfaces be cut or turned to the desired size.

Fig. 16 a fragmentary portion of article III own having typical surfacesI! and Id at te ends of and at right angles to an intervening surfaceIIb, and surface lic and Ile at right angles to each other with a curveor fillet 161 comprising their junction point. 'Ihe surfaces Il, Ib,itc, iid and Ile are cut or turned surfaces, the metal cut or turnedtherefrom bein! typically shown in dotted lines, while surface I'Bg isthe virgin metal of article Il. The surfaces iid, Il and ite are adaptedto be cut or turned by the cutting edge I2. In cutting or turning todimension the surfaces Il, IIb the tool II shown in Hgo. 4, 5, 8, 9, l2through 1.5, or that of Fig. 1l, may be employed. Its outer or tip endcutting edge IU, I2c or I2p may be set to the plane of surface IIb andsuccessive cuts made with the right angled cutting edges of either ofsuch cutters or turning tools II, until the surfaces I8, lib arefinished. In cutting or turning to dimension the surfaces Ic, Iieand IBIthe tool Il of Pigs. 6, 7, or l may be employed in like manner as nextbefore stated in which its cutting edge I2 cuts or turns the surfacelic, as well as at its last cut leaves the curve or flllet if while thecutting edge I2 at its last cut leaves the surface itc. In cutting orturning the surface IIb, the cutting edge |21 of Figs. 4, 5. cold worksthe metal as it progressively cuts or turns the same to thedesireddimension. ,In such cutting and cold working the flowageof metal alongcutting edge I2 toward the outer or tip end of 'cutter or turning toolII, continues onto and along, as well as over, the angular cutting edge|21. While such flowage may not be the sole cause of such cold working,we have foundl that the metal of the surface of articles Il cut by saidcutting edge I2i is superior in many desirable respects to thatresulting from cutting or turning in accordance with prior practice.

In the cutting of surfaces I8 and'IBb with the tool of Fig. 1l, thenotch I2m initially increases the top rake of the cutting edges I2, I2pwithin the area of such notch by in said area increasing the angle ofthe side rake surface of tool II, which, with the metal severed bycutting edges I2 and I2p simultaneously flowing at right angles to eachother into notch I2m, each increases the reluctance to owage of thesevered metal from notch I21n and over the beveled side rake surface Ilbelow notch or nick I2m, and adds substantially to the cold workingeffect upon the surface Iib, throughout its extent, and of surface Ii inthe region of surface Iib of the metal -of article Il cut or turned bytool II.

4 The action of notch or nick I2m of Figs. 6, 'l and is similar to thatjust described.

When the tool II is employed for turning metal the relation of' itscutting edges, nicks and grooves to the neutral axis of the article Il!being turned thereby contributes to the cold working of the metal of itssurface. In such practice the tool II is preferably set straight in thetool post of the lathe, screw machine, or other turning machine-toolwith its outer or tip end set such that the apex of its cutting edgesI2, |21, or I2, I2n, or I2, I2p is on a horizontal plane slightly belowthat in which lies the neutral axis of the article Il'being turned todimension. The substantial increase of the cold working value of the toprake of either of the lateral cutting edges |21, I2n, I2p is occasionedby the nick therein, as well as by said nick being slightly beveled withits high side progressing along its approprie. lateral cutting edge andhighest at the cutting edge I2. Buch nick, while cutting only surfaceIIb or Ic, increases the top rake of the lateral cutting edge of thecutter II, while the bevel of said nick further increases the reluctanceof the now of the cut metal thereover by changing the direction of suchow to at less than a right angle due to its contact with metal cut fromsurface lib or Ic, according to the bevel of said nick. When either ofthe pair of surfaces I6, lib, or ite, itc are being simultaneously cut,the metal of article Il in the region of the point of juncture of suchpair of surfaces is cold worked to a greater extent due to the increasedincreased reluctance of the flow of cut metal over the tip or outer endof the tool II that is cut from such region.

The longitudinal as well as transverse arch of the side rake surface Ilof the tool II of Figs. v

4, 5, 'I and 8 and the arched effect of the shaving Il, as yetunseparated from article Il at its opposite sides, each substantiallyincrease the reluctance of shaving I1 to passing over these arches ofthe side rake surface Il in cuttingl as well as in turning and therebyfurther increase the cutting thrust of such tool II and the cold workingeffect upon the metal of the surface of article I0 being cut thereby.

Any number of the heretofore described means for increasing the coldworking effect thereof upon the metal in the region of the line of itscleavage may be employed on a single cutter or turning tool II uniformlydisposed throughout the extent of its cutting edge I2, or localized,accordingly as a uniform or a localized cold working may be desired, aswell as to obtain the :lesired extent of such cold working.

In prior turning practice the cutting edge -IZ of tool II is straightand lies in a horizontal plane passing within one thirty-second of aninch of the neutral axis of article I0, while in the present inventionsuch edge meanders from a point much below such axis to and/or abovesuch axis, which we have found increases the cold working effect of suchcutting edge upon the metal of the surface of article Il turned thereby.

All of the metal of the surfaces of article I0, being cold worked whilebeing cut as heretofore described, is transformed by such cold workingand cutting, which renders said metal tougher and more resistant towear, corrosion, and other deterioration, as well as forms a surface ofa finish and other characteristics which we have found more satisfactoryin service than articles which have heretofore merely been normally cutor turned. While such metal does not possess all of the characteristicsof case-hardened or heat treated metal, it is superior for manypurposes, to and costs practically no more than, metal which has beenmerely normally cut or turned pursuant to prior practices.

It will be observed that by our invention, any article of a coldworkable metal or alloy having a virgin cut or turned surface-that is.such surface as is cut or turned in vaccordance with our invention,without being otherwise treated or acted upon-is of metal ofsubstantially different characteristics than the adjacent similar metalof the article; and that such transforma- 7o tion, of thecharacteristics of the metal of the surface or surfaces of any articleformed by being cut or turned according to our invention, substantiallyincreases the strength, toughness, wear and corrosion resistance of suchmetal, and other- `als wise renders it morey advantageous for many kindsof service.

It may be understood from the foregoing, by those skilled-in the art,that the before-described cold Working of the cold workable metal,simultaneously with and by the manner of its cutting or turning,produces a transitory stress progressively along its surface being cutor turned and which stresses the metal in the region of such cutting orturning to a point beyond its elasticlimit but not beyond its point offracture. This cold working substantially increases the strength andtoughness of the metal, its surface density and nish, as well as itsresistance to corrosion and wear at and adjacent the line oi cleavageeffected in accordance with our invention.

Before our invention it was unknown thatv solely by cutting or turning ametal article, or a shaving therefrom, that such article or shaving maypossess greater strength, toughness, surface density and nish, as Wellas resistance to corrosion and Wear than was possessed by thev parentmetal before being so cut or turned.

We were rst in the art to solve the hereto-v fore long and vainly soughtproblem of inexpensively and expeditiously producing such changedadvantageous characteristics by and simultaneously with the cutting orturning of any article of cold workable metal which normally did notpossess such characteristics. In our solution of said problem we employcold workable metal in the cheaper form of such metal which does notnormally possess such characteristics. We abnormally cut .or turn themetal article, or at least a portion of a surface thereof, and

thereby transform the metal lof and adjacent such cut or turned surface,or surfaces, to the before stated characteristics. Such transformationresults from the abnormal cutting or turning in accordance with ourinvention, which stresses the metal adjacent its line of cleavage to anextent beyond its elastic limit and below its point of fracture. Undersuch stress'a flowage of the metal occurs at and in the region of itsline of cleavage, although the metal maybe under atmospheric temperatureexcept for such stress. Such flowage cold works metal of the article andtransforms the same into characteristics which we have found veryeconomical and advantageous.

We were first to cold work metal of an article by and simultaneouslywith the cutting or turning of the same, by our process and tool, from alarger piece of metal whose normal characteristics did not disclose, butwhich our said cold working by cutting or turning transforms intocharacteristics which we have found useful and advantageous for articlesrequired in normal, as well as in severe, service conditions. Suchtransformation by cold Working of metal occurs in the shaving or portioncut or turned` by our process and tool from the parent metal, as well asin the metal of the surface of the parent article from which the shavingor portion was cut or turned.

We are aware of a prior practice, termed Auto frettage, wherein highpressure liquid is directly applied within an ordnance bore to outwardlystress and stretch the metal of the wall of such bore beyond its elasticlimit, but below its fracture point, to thereby transform the charourinvention. Such cleavage is occasioned by A stressing the metal alongsuch line of cleavage at least to the shearing point, While at least themetal adjacent such line is subjected to compression stress beyond itselastic limit, but below its fracture point. We have found that suchstressing may be associated with and occasioned by abnormal cleavage,and that the same beneficially transforms the characteristics of themetal of such stressed and cleaved article at least in the region of theline of cleavage. While the stressing of the metal involves theapplication of force in excess of that required for the normal cuttingor turning of a given article, the magnitude of such stress is verymaterially reduced by the stressing being progressively and successivelyapplied to different relatively small areas, preferably extendingthroughout the surface'bf the metal whose characteristics are to betransformed thereby. This also materially reduces the magnitude of thepower required in the practice of our invention, as Well as reduces thestress and wear upon the machine and the cutting or turning tools whichmay be required by such practice of simultaneously cutting or turning atleast a surface of an article and cold workingmetal of such surface intostronger and tougher metal of increased density and resistance to wearand Corrosion, with no more time and labor, and with but little morepowermm Having now described our invention so fully that those skilledin this art may therefrom make and use the same, what we claimv anddesire to secure by Letters Patent is:

1. A tool for turning metal having an arched cutting edge and an archedside rake surface.

2. A. tool for turning metal having an arched cutting edge extendinglongitudinally of the tool and an arched side rake surface.

3. A tool for turning metal having an arched cutting edge and a siderake surface arched in two directions.

4. A tool for turning metal having a cutting edge, a side rake surface,at least one nick in the cutting edge, and a groove extending from saidnick at least partially across said side rake surface.

5. A tool for turning metal having a meandering cutting edge, an archedside rake surface,

at least one nick in the cutting edge, and a ALFRED J. BERG. JOHN O.HUSE.

